/*
	B A S E 6 4. C P P

	Copyright (C) 2013 Sumscope SoftWare

	Version: 0.0.1
*/

#include "base64.h"
#include <string.h>

///////////////////////////////////////////////////////////////////////////////////
/// The usefull base64 encoder and decoder

#define MAXLINE  76

/*============================================================================
 * Everything below this line is private to this file (static)
 *============================================================================
 */

namespace qb
{
    static char base64tab[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        "abcdefghijklmnopqrstuvwxyz0123456789+/";

    static char base64idx[128] = {
        '\377','\377','\377','\377','\377','\377','\377','\377',
        '\377','\377','\377','\377','\377','\377','\377','\377',
        '\377','\377','\377','\377','\377','\377','\377','\377',
        '\377','\377','\377','\377','\377','\377','\377','\377',
        '\377','\377','\377','\377','\377','\377','\377','\377',
        '\377','\377','\377',    62,'\377','\377','\377',    63,
            52,    53,    54,    55,    56,    57,    58,    59,
            60,    61,'\377','\377','\377','\377','\377','\377',
        '\377',     0,     1,     2,     3,     4,     5,     6,
             7,     8,     9,    10,    11,    12,    13,    14,
            15,    16,    17,    18,    19,    20,    21,    22,
            23,    24,    25,'\377','\377','\377','\377','\377',
        '\377',    26,    27,    28,    29,    30,    31,    32,
            33,    34,    35,    36,    37,    38,    39,    40,
            41,    42,    43,    44,    45,    46,    47,    48,
            49,    50,    51,'\377','\377','\377','\377','\377'
    };

    static char hextab[] = "0123456789ABCDEF";
    static char eol_string[] = "\r\n";

#ifdef __cplusplus
    inline int isbase64(int a) {
        return ('A' <= a && a <= 'Z')
            || ('a' <= a && a <= 'z')
            || ('0' <= a && a <= '9')
            || a == '+' || a == '/';
    }
#else
#define isbase64(a) (  ('A' <= (a) && (a) <= 'Z') \
                    || ('a' <= (a) && (a) <= 'z') \
                    || ('0' <= (a) && (a) <= '9') \
                    ||  (a) == '+' || (a) == '/'  )
#endif


    int encode_base64(const char* aIn, size_t aInLen, char* aOut,
        size_t aOutSize, size_t* aOutLen)
    {
        size_t inLen = 0;
        char* out = 0;
        size_t outSize = 0;
        size_t inPos = 0;
        size_t outPos = 0;
        int c1, c2, c3;
        int lineLen = 0;
        size_t i;
        const char* cp = 0;


        if (!aIn || !aOut || !aOutLen)
            return -1;
        inLen = aInLen;
        out = aOut;
        outSize = (inLen + 2) / 3 * 4;     /* 3:4 conversion ratio */
        outSize += strlen(eol_string) * outSize / MAXLINE + 2;  /* Space for newlines and NUL */
        if (aOutSize < outSize)
            return -1;

        /* Get three characters at a time and encode them. */
        for (i = 0; i < inLen / 3; ++i) {
            c1 = aIn[inPos++] & 0xFF;
            c2 = aIn[inPos++] & 0xFF;
            c3 = aIn[inPos++] & 0xFF;
            out[outPos++] = base64tab[(c1 & 0xFC) >> 2];
            out[outPos++] = base64tab[((c1 & 0x03) << 4) | ((c2 & 0xF0) >> 4)];
            out[outPos++] = base64tab[((c2 & 0x0F) << 2) | ((c3 & 0xC0) >> 6)];
            out[outPos++] = base64tab[c3 & 0x3F];
            lineLen += 4;
            if (lineLen >= MAXLINE - 3) {
                cp = eol_string;
                out[outPos++] = *cp++;
                if (*cp) {
                    out[outPos++] = *cp;
                }
                lineLen = 0;
            }
        }
        /* Encode the remaining one or two characters. */
        switch (inLen % 3) {
        case 0:
            cp = eol_string;
            out[outPos++] = *cp++;
            if (*cp) {
                out[outPos++] = *cp;
            }
            break;
        case 1:
            c1 = aIn[inPos] & 0xFF;
            out[outPos++] = base64tab[(c1 & 0xFC) >> 2];
            out[outPos++] = base64tab[((c1 & 0x03) << 4)];
            out[outPos++] = '=';
            out[outPos++] = '=';
            cp = eol_string;
            out[outPos++] = *cp++;
            if (*cp) {
                out[outPos++] = *cp;
            }
            break;
        case 2:
            c1 = aIn[inPos++] & 0xFF;
            c2 = aIn[inPos] & 0xFF;
            out[outPos++] = base64tab[(c1 & 0xFC) >> 2];
            out[outPos++] = base64tab[((c1 & 0x03) << 4) | ((c2 & 0xF0) >> 4)];
            out[outPos++] = base64tab[((c2 & 0x0F) << 2)];
            out[outPos++] = '=';
            cp = eol_string;
            out[outPos++] = *cp++;
            if (*cp) {
                out[outPos++] = *cp;
            }
            break;
        }
        out[outPos] = 0;
        *aOutLen = outPos;
        return 0;
    }

    int decode_base64(const char* aIn, size_t aInLen, char* aOut,
        size_t aOutSize, size_t* aOutLen)
    {
        size_t inLen = 0;
        char* out = 0;
        size_t outSize = 0;

        int isErr = 0;
        int isEndSeen = 0;
        int b1, b2, b3;
        int a1, a2, a3, a4;
        size_t inPos = 0;
        size_t outPos = 0;

        if (!aIn || !aOut || !aOutLen)
            return -1;
        inLen = aInLen;
        out = aOut;
        outSize = (inLen + 3) / 4 * 3;
        if (aOutSize < outSize)
            return -1;
        /* Get four input chars at a time and decode them. Ignore white space
         * chars (CR, LF, SP, HT). If '=' is encountered, terminate input. If
         * a char other than white space, base64 char, or '=' is encountered,
         * flag an input error, but otherwise ignore the char.
         */
        while (inPos < inLen) {
            a1 = a2 = a3 = a4 = 0;
            while (inPos < inLen) {
                a1 = aIn[inPos++] & 0xFF;
                if (isbase64(a1)) {
                    break;
                }
                else if (a1 == '=') {
                    isEndSeen = 1;
                    break;
                }
                else if (a1 != '\r' && a1 != '\n' && a1 != ' ' && a1 != '\t') {
                    isErr = 1;
                }
            }
            while (inPos < inLen) {
                a2 = aIn[inPos++] & 0xFF;
                if (isbase64(a2)) {
                    break;
                }
                else if (a2 == '=') {
                    isEndSeen = 1;
                    break;
                }
                else if (a2 != '\r' && a2 != '\n' && a2 != ' ' && a2 != '\t') {
                    isErr = 1;
                }
            }
            while (inPos < inLen) {
                a3 = aIn[inPos++] & 0xFF;
                if (isbase64(a3)) {
                    break;
                }
                else if (a3 == '=') {
                    isEndSeen = 1;
                    break;
                }
                else if (a3 != '\r' && a3 != '\n' && a3 != ' ' && a3 != '\t') {
                    isErr = 1;
                }
            }
            while (inPos < inLen) {
                a4 = aIn[inPos++] & 0xFF;
                if (isbase64(a4)) {
                    break;
                }
                else if (a4 == '=') {
                    isEndSeen = 1;
                    break;
                }
                else if (a4 != '\r' && a4 != '\n' && a4 != ' ' && a4 != '\t') {
                    isErr = 1;
                }
            }
            if (isbase64(a1) && isbase64(a2) && isbase64(a3) && isbase64(a4)) {
                a1 = base64idx[a1] & 0xFF;
                a2 = base64idx[a2] & 0xFF;
                a3 = base64idx[a3] & 0xFF;
                a4 = base64idx[a4] & 0xFF;
                b1 = ((a1 << 2) & 0xFC) | ((a2 >> 4) & 0x03);
                b2 = ((a2 << 4) & 0xF0) | ((a3 >> 2) & 0x0F);
                b3 = ((a3 << 6) & 0xC0) | (a4 & 0x3F);
                out[outPos++] = (char)(b1);
                out[outPos++] = (char)(b2);
                out[outPos++] = (char)(b3);
            }
            else if (isbase64(a1) && isbase64(a2) && isbase64(a3) && a4 == '=') {
                a1 = base64idx[a1] & 0xFF;
                a2 = base64idx[a2] & 0xFF;
                a3 = base64idx[a3] & 0xFF;
                b1 = ((a1 << 2) & 0xFC) | ((a2 >> 4) & 0x03);
                b2 = ((a2 << 4) & 0xF0) | ((a3 >> 2) & 0x0F);
                out[outPos++] = (char)(b1);
                out[outPos++] = (char)(b2);
                break;
            }
            else if (isbase64(a1) && isbase64(a2) && a3 == '=' && a4 == '=') {
                a1 = base64idx[a1] & 0xFF;
                a2 = base64idx[a2] & 0xFF;
                b1 = ((a1 << 2) & 0xFC) | ((a2 >> 4) & 0x03);
                out[outPos++] = (char)(b1);
                break;
            }
            else {
                break;
            }
            if (isEndSeen) {
                break;
            }
        } /* end while loop */
        *aOutLen = outPos;
        return (isErr) ? -1 : 0;
    }

    int EncodeBase64(std::string& strSrc, std::string& strDest)
    {
        size_t destSize = 4 * (strSrc.length() + 2) / 3;
        destSize += strlen("\r\n") * destSize / 72 + 2;
        destSize += 64; /*64;  a little extra room */

        /* Allocate destination buffer */
        char* destBuf = new(std::nothrow) char[destSize];
        if (0 == destBuf)
        {
            //strDest.ReleaseBuffer();
            return false;
        }

        /* Encode source to destination */
        size_t destLen = 0;
        int result = encode_base64(strSrc.c_str(), strSrc.length(), destBuf, destSize, &destLen);
        if (destLen < destSize)
            destBuf[destLen] = '\0';

        //strDest.ReleaseBuffer();
        strDest = destBuf;
        if (destBuf) delete[]destBuf;
        return strDest.length();
    }

    int DecodeBase64(std::string& strSrc, std::string& strDest)
    {
        size_t destSize = 4 * (strSrc.length() + 2) / 3;
        destSize += strlen("\r\n") * destSize / 72 + 2;
        destSize += 64; /*64;  a little extra room */

        /* Allocate destination buffer */
        char* destBuf = new(std::nothrow) char[destSize];
        if (0 == destBuf)
        {
            //strDest.ReleaseBuffer();
            return false;
        }

        /* Encode source to destination */
        size_t destLen = 0;
        int result = decode_base64(strSrc.c_str(), strSrc.length(), destBuf, destSize, &destLen);
        if (destLen < destSize)
            destBuf[destLen] = '\0';

        strDest = destBuf;
        if (destBuf) delete[] destBuf;
        return strDest.length();
    }

    //////////////////////////////////////////////////////////////////////////
    // CRC32 and CRC16

    static unsigned int crc_32_tab[] = {
            0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
            0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
            0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
            0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
            0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
            0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
            0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
            0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
            0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
            0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
            0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
            0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
            0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
            0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
            0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
            0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
            0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
            0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
            0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
            0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
            0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
            0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
            0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
            0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
            0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
            0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
            0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
            0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
            0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
            0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
            0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
            0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
            0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
            0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
            0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
            0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
            0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
            0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
            0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
            0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
            0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
            0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
            0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
            0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
            0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
            0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
            0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
            0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
            0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
            0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
            0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
            0x2d02ef8dL
    };

    unsigned int CRC32(char* s, int len)
    {
        register unsigned c;
        unsigned int crc = (unsigned int)0xffffffffL;

        if (s == 0)
        {
            c = 0xffffffffL;
        }
        else
        {
            c = crc;
            if (len)
            {
                do
                {
                    c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
                } while (--len);
            }
        }
        crc = c;
        return c ^ 0xffffffffL;
    }

    WORD CRC16(unsigned char* info, DWORD len)
    {
        WORD acc;
        unsigned char i;
        acc = 0;
        while (len--)
        {
            acc = acc ^ (((unsigned int)(*info)) << 8);
            info++;
            for (i = 8; i > 0; i--)
            {
                if (acc & 0x8000)
                    acc = (acc << 1) ^ 0x1021;
                else acc <<= 1;
            }
        }
        return acc;
    }

}
